1. Field of the Invention
The present invention relates to a slat which is attached to a main wing of an aircraft to generate a high lift, and a mechanism which adjusts an attachment position of the slat to the main wing.
2. Description of the Related Art
A slat as a high-lift device is provided at a main wing of an aircraft. The slat is provided along a leading edge of the main wing. The slat performs an operation required for generating a high lift by a drive mechanism. The slat moves to a deployed position so as to increase a lift during takeoff and landing. Accordingly, in the entire main wing including the slat, a wing side surface has a larger curvature, and a length in a wing chord direction is extended. When the slat is at the deployed position, a gap is formed between a trailing edge of the slat and the leading edge of the main wing. High-energy air is supplied to the gap from bottom up.
The slat needs to be arranged on the main wing with no gap therebetween at a retracted position so as not to disturb a flow of air relative to the main wing. Meanwhile, the gap (value) with the main wing at the deployed position needs to be rigorously controlled so as to obtain a required lift and form an upward flow of air in the gap. Therefore, it is necessary to attach the slat to the main wing with high positional accuracy. Japanese Patent Laid-Open No. 2000-211594 discloses a method for performing fine adjustment (also referred to as rigging) of a position at which the slat is attached to the main wing by use of a gauge.
The slat is attached to a bracket, typically, to a rail. The above fine adjustment of the position is performed by finely adjusting the position of the slat with respect to the rail at the retracted position. However, the rail reciprocates along a predetermined movement path with respect to the main wing. The position of the slat with respect to the rail is thus synonymous with the position of the slat with respect to the main wing. The same applies to the deployed position. The position of the slat with respect to the rail is finely adjusted such that the gap between the slat and the main wing has a required gap value with the slat moved forward to the deployed position.
The slat includes a position adjustment mechanism which performs the fine adjustment. The conventional position adjustment mechanism causes the slat to reciprocate while moving in an arc trajectory with respect to the rail. For example, the position adjustment mechanism includes a configuration shown in FIG. 9 (Author: Michael C. Y. Niu, Translator: Kenichi Doi, Mamoru Makishima, “Airframe Structural Design: Practical Design Information and Data on Aircraft Structures”, Nagoya Kouku Gijutsu (Nagoya Aviation Technology), Feb. 21, 2000, p. 345).
A position adjustment mechanism 100 shown in FIG. 9 causes a slat 103 to swing by applying a three-point link mechanism between the slat 103 and a rail 112.
That is, a pivot shaft S101 is caused to work as a swing rotation center by supporting the slat 103 and the rail 112 on the pivot shaft S101 so as to allow relative rotation therebetween. A link member 106 is also provided between the slat 103 and the rail 112. The slat 103 and the link member 106 are supported so as to allow relative rotation therebetween by a fixed shaft S102, and the rail 112 and the link member 106 are supported so as to allow relative rotation therebetween by a driving shaft S103. The driving shaft S103 includes an eccentric shaft E. The link member 106 is locked to the eccentric shaft E. Thus, when the driving shaft S103 is rotated, the slat 103 can be caused to swing about a swing axis composed of the pivot shaft S101.
In the rigging, the driving shaft S103 is rotated so as to bring a trailing edge 103b of the slat 103 into contact with a main wing 1 with no gap therebetween when the slat 103 is at the retracted position. After that, it is checked whether the gap between the slat 103 and the main wing 1 has a required gap value when the slat 103 is moved to the deployed position.
The position adjustment mechanism 100 in FIG. 9 has a following problem.
As shown in FIG. 9, a swing arm 104 that supports the pivot shaft S101 and the fixed shaft S102 is provided integrally with the slat 103 so as to constitute the three-point link mechanism. That is, the swing arm 104 is larger than a distance between the pivot shaft S101 and the fixed shaft S102, and arranged within a main wing body 102. It is thus necessary to provide a cutout in a leading edge 102a of the main wing body 102 so as to allow the swing arm 104 to reciprocate therein. The cutout could disturb an air current flowing between the slat 103 and the main wing body 102 when the slat 103 is deployed. The cutout is thus preferably made smaller. Especially when the main wing body 102 is thin, the size of the cutout is fatal even when the same three-point link mechanism is used. This is because an air current received from a front side enters the cutout to form a vortex and become resistance. When the main wing is thin, it is particularly necessary to decrease the size of the cutout so as to cause the air current to flow along the surfaces of the slat 103 and the main wing body 102 by avoiding the cutout.
In the position adjustment mechanism 100, the pivot shaft S101 is distant from a leading edge 103a of the slat 103, and the slat 103 has a large rotation radius about the pivot shaft S101. Therefore, when the driving shaft S103 is rotated in the rigging, a travel distance of the slat 103 per unit rotation angle is increased. It is thus difficult for the position adjustment mechanism 100 to perform the rigging while moving the slat 103 little by little.
Thus, an object of the present invention is to provide a slat which can stabilize an air current flowing between the slat and a main wing by decreasing the size of a cutout in the main wing required for providing a position adjustment mechanism.
Another object of the present invention is to provide a slat which can facilitate a rigging operation by locating a pivot position of a swing motion of the slat closer to a leading edge of the slat, and thereby decreasing a unit travel distance of the slat in the rigging.